The DS1260 SmartBattery is a low-cost, backup energy supply for portable and nonvolatile electronic equipment. A lithium energy source of up to 1 amp hour can supply power to CMOS electronic circuits when primary power is lost through an intelligent and efficient switch. When power is supplied from the lithium power source, the power fail signal is held low to warn electronic (RESET) circuits of the power status. Energy loss during shipping and handling is avoided by pulsing RESET, thereby causing the backup energy source to be isolated from the exposed pins. The DS1260 can be plugged into a standard 16-pin, low-cost DIP socket, allowing for proven interconnect and simple replacement if the energy has been exhausted.